efalizumab + methotrexate

Efalizumab + methotrexate is a combination therapy involving two distinct drugs used primarily in the management of moderate to severe chronic plaque psoriasis. Efalizumab is a recombinant, humanized monoclonal IgG1 antibody that targets CD11a, a subunit of lymphocyte function-associated antigen-1 (LFA-1), thereby inhibiting T-cell activation and migration involved in the inflammatory process of psoriasis[4][9]. Methotrexate is a small molecule antimetabolite and antifolate agent that inhibits dihydrofolate reductase, leading to suppression of DNA synthesis and immunosuppressive effects. The combination has been used off-label for patients with inadequate response or symptom exacerbation during efalizumab monotherapy; short-term addition of methotrexate can help control disease flares without significantly increasing adverse events[1][3]. Efalizumab was developed by Genentech/Serono but has been withdrawn from many markets due to safety concerns unrelated to this specific combination.